The broad objective of this research project is twofold: first, to identify biochemical events which are necessary for the repair of injured neural tissue as distinguished from those which are secondary or even detrimental; and second, to elucidate factors which intensify those events related to the repair process and inhibit those which retard regeneration of neural tissue. Goals set for the current year include: (a) developing a system to explore biochemical correlates of neurite outgrowth from adult differentiated neural tissue in culture; (b) investigating mechanisms associated with increases in 6-phosphogluconate dehydrogenase in axotomized rat superior cervical ganglia; (c) examine whether transected peripheral and central fiber tracts of hibernating ground squirrels survive and regenerate to a greater degree than those from non-hibernating animals. More information than now exists is necessary to define interactions between pre- and postsynaptic elements which alter the anabolic response of nerve cell bodies to axonal injury. The superior cervical ganglia in culture offers a model to define these interactions. Basic information gained in these studies could provide insight necessary for understanding and treating a number of tragic human conditions such as paraplegia and stroke, which are related directly to failure of neural tissues to regenerate.